Real estate sales data used by the Cook County Assessor to estimate Fair Cash Values for the purpose of property taxation. Deeds that include multiple PIN numbers are excluded from this data. This data is produced by joining sales data from the Illinois Department of Revenue against incomplete sales data from the Cook County Recorder of Deeds, parsing the resulting data to obtain data unique by deed number, and, in some cases, determining arms' length status of sales.

This data set includes property locations and attached spatial data for all Cook County parcels. Spatial matching was based on parcel centroids. Older properties may be missing latitude and longitude data because they are not contained in the most recent parcel shape layer. Brand new properties may be missing a mailing/property address because the postal service has not yet assigned the property an address. Data attached to each PIN is the most recent available. For example, Census tract data is drawn from the 2014-2018 5-year American Community Survey.

The code and sources used to construct this data can be located on GitLab. See data notes for link.

The feature class LOT contains lot polygons as shown on the tax map.

The Parcel 2016 feature contains tax parcel polygons for the 2016 property tax assessment at the County. This feature reflects tax parcel polygons as they existed from 1/1/2016 through 12/31/2016. Each parcel is uniquely identified with a Property Index Number (PIN).

Building Footprints based off data from 2008 for the buildings and 2010 vintage for UV SAL buildings in Cook County that are outside of the Chicago Open Data (which is various dates as collected)

2008 Cook County Lidar, UVM Spatial Analysis Lab 2010 Chicago Regional Land Cover (2008 Lidar building footprints were extracted using Esri software and UVM Spatial Analysis Lab building footprints were extracted/regularized using Esri software).

Building Footprints based off data from 2008 for the buildings and 2010 vintage for UV SAL buildings in Cook County that are outside of the Chicago Open Data (which is various dates as collected)

2008 Cook County Lidar, UVM Spatial Analysis Lab 2010 Chicago Regional Land Cover (2008 Lidar building footprints were extracted using Esri software and UVM Spatial Analysis Lab building footprints were extracted/regularized using Esri software).

Department of GIS sponsored Municipal Incorporation Inventory (MII) project. The following agencies participated in this project: The Cook County Recorder of Deeds, Cook County Emergency Telephone System Board, Cook County Circuit Court, Archives Department, Cook County Department of Transportation and Highways, the Cook County Clerk’s Office and the Illinois State Archives Office of the Secretary of State.

The data is not guaranteed to be accurate, correct, or complete. Information provided should not be used as a substitute for legal, business, tax, or other professional advice. The recipient/viewer should contact appropriate regulating agencies to determine accuracy or suitability of the data for a particular use.

The feature class LOT contains lot polygons as shown on the tax map.

The Parcel 2015 feature contains tax parcel polygons for the 2015 property tax assessment at the County. This feature reflects tax parcel polygons as they existed from 1/1/2015 through 12/31/2015. Each parcel is uniquely identified with a Property Index Number (PIN).

This Address Point feature class contains one point for every address in Survey Township 33 (Township 35 N, Range 15 E; see ccgisdata - Survey Township (Area) 2014).